Microbiology spectrum最新文献

{"title":"<i>piv</i> does not impact <i>Pseudomonas aeruginosa</i> virulence in <i>Galleria mellonella</i>.","authors":"Rachel E Robinson, Joshua K Robertson, Dina A Moustafa, Joanna B Goldberg","doi":"10.1128/spectrum.02811-24","DOIUrl":"https://doi.org/10.1128/spectrum.02811-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> is an opportunistic human pathogen that can also infect mammals, invertebrates, and plants. Protease IV (PIV) is a secreted protease shown to be important in mammalian cornea, lung, and wound models of infection. It also contributes to <i>P. aeruginosa</i> virulence in many invertebrate models. Previous studies have shown that the expression of the gene encoding PIV is higher at 25°C than at 37°C. Thus, we hypothesized that <i>piv</i> would be more important for <i>P. aeruginosa</i> virulence at 25°C than at 37°C. To test this, we first demonstrated that more PIV is secreted by <i>P. aeruginosa</i> PAO1 cells grown at 25°C than at 37°C. We then determined the survival of larvae of the greater wax moth <i>Galleria mellonella</i> infected by PAO1 and an isogenic Δ<i>piv</i> mutant at both 25°C and 37°C. We found no significant difference in virulence between PAO1 and Δ<i>piv</i> at either 25°C or 37°C, although both strains were more virulent at 37°C than 25°C as measured by a decrease in median survival time. <i>P. aeruginosa</i> possesses an arsenal of virulence factors besides PIV, and thus loss of this single virulence factor may not result in attenuation in the highly susceptible <i>G. mellonella</i> larvae.IMPORTANCEPathogenesis of the important opportunistic pathogen <i>Pseudomonas aeruginosa</i> is often investigated using model organisms. Larvae of the greater wax moth, <i>Galleria mellonella</i>, are a popular non-mammalian model organism for <i>P. aeruginosa</i> infections that have been used to study highly attenuated mutants and characterize their defects in virulence. Our study shows that small differences in the virulence of <i>P. aeruginosa</i>, such as those caused by deleting the gene encoding a single virulence factor, may not be detectable in the <i>G. mellonella</i> model of infection. This is an important finding for researchers considering the choice of model organisms for virulence studies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0281124"},"PeriodicalIF":3.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial resistance and molecular characteristics of bovine mastitis-associated methicillin-resistant <i>Staphylococcus aureus</i>: potential for cross-species transmission of ST59-MRSA.","authors":"Wen Sun, Jiayi Liu, Shuangshuang Li, Xiaoman Zhu, Xiangyun Wu, Baojing Dou, Xiaomin Pang, Keke Tian, Peipei Wang, Haihong Hao, Yulian Wang","doi":"10.1128/spectrum.02800-24","DOIUrl":"https://doi.org/10.1128/spectrum.02800-24","url":null,"abstract":"<p><p>Mastitis caused by methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) is a common issue in dairy farming, with sequence types (STs) related to cows mainly including ST9 and ST97. ST59, the predominant community-acquired clone, is still less reported in dairy cows. This study investigated the antimicrobial resistance patterns and molecular characteristics of 77 <i>Staphylococcus aureus</i> isolates obtained from eight dairy farms in the mid-east of China during 2019-2020, focusing particularly on the bovine mastitis-related livestock-associated MRSA (LA-MRSA) clone ST59. Among the 77 isolates, 14 isolates were identified as MRSA. A total of 20 STs were identified, with ST59 being the most prevalent among MRSA isolates (35.7%). All MRSA isolates possessed various Staphylococcal cassette chromosome <i>mec</i> (SCC<i>mec</i>) types, including XII (<i>n</i> = 5), IV.a (<i>n</i> = 4), IV.c (<i>n</i> = 2), IV.g (<i>n</i> = 2), and V (<i>n</i> = 1). Three MRSA lineages were identified: MRSA-ST59-t437-SCC<i>mec</i> IV.a/IV.g (<i>n</i> = 5), MRSA-ST9-t899-SCC<i>mec</i> XII (<i>n</i> = 4), and MRSA-ST88-t3622-SCC<i>mec</i> IV.c (<i>n</i> = 2). Approximately 44.2% of isolates demonstrated multidrug resistance. MRSA isolates showed a higher prevalence of antimicrobial resistance compared to methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA) isolates. Virulence factor assays revealed that all MRSA isolates carried at least hemolysin genes and enterotoxin genes. ST59-MRSA strains showed the closest genetic relationship with human-derived strains, indicating a potential public health risk due to transmission of <i>Staphylococcus aureus</i> between livestock and humans. This study highlights the significant prevalence of the bovine mastitis-related LA-MRSA clone ST59 in the mid-east of China. Therefore, reinforcing monitoring and implementing preventive measures are essential to combat LA-MRSA.</p><p><strong>Importance: </strong>Obtained the prevalence and molecular characteristics of <i>Staphylococcus aureus</i> in dairy farms in the mid-east of China from 2019 to 2020. Recently identified livestock-associated methicillin-resistant <i>S. aureus</i> (LA-MRSA) clones in cattle, including ST59-MRSA, may have originated from human sources, suggesting a potential risk for interspecies transmission.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0280024"},"PeriodicalIF":3.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A relationship between body size and the gut microbiome suggests a conservation strategy.","authors":"Tong Xin, Qian Ye, Dini Hu","doi":"10.1128/spectrum.00294-25","DOIUrl":"https://doi.org/10.1128/spectrum.00294-25","url":null,"abstract":"<p><p>A key goal of conservation is to protect the biodiversity of wild species to support their continued evolution and survival. Conservation practice has long been guided by genetic, ecological, and demographic indicators of risk. Cope's rule suggests that species tend to evolve larger body sizes over time. Here, we provide strong evidence to support the inclusion of body size when formulating wildlife conservation strategies. The gut microbiome can mirror the physiological and environmental adaptation status of the host. This study established a connection between body size and the gut microbiome in the Felidae family using 70 fecal samples collected from 18 individuals through metagenomic data analysis and mining metagenome-assembled genomes (MAGs). Two enterotypes were identified in the Felidae gut: <i>Bacteroides</i> and <i>Clostridium</i>. Medium-sized felids predominantly harbored <i>Clostridium</i>, associated with pathogenicity, whereas large and small felids harbored both beneficial <i>Bacteroides</i> and pathogenic <i>Clostridium</i>. Species that evolved larger body sizes over time exhibited distinct changes in gut microbial communities, such as enhanced nutrient extraction and metabolic capabilities. Larger felids exhibited a more diverse, stable gut microbiome engaged in metabolic processes and extensive host interactions, indicating an evolved functional role in various biological processes. Conversely, that of smaller felids is less diverse, with more viruses and pathogenic elements primarily involved in chemical synthesis. These findings provide essential insights for developing conservation strategies that consider the nutritional needs of different-sized feline species, control the transmission of pathogens, and allocate resources based on their unique gut microbiome characteristics.IMPORTANCEBody size is a fundamental trait that varies greatly among taxa and has important implications for life history and ecology. Cope's rule suggests that species tend to evolve larger body sizes over time. However, its correlation to body size evolution remains unclear. This study aimed to establish a connection between body size and the gut microbiome in the Felidae family through metagenomic data analysis. Our results support Cope's rule, illustrating that increased body size correlates with shifts in the gut microbiome, enhancing survival and adaptability.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0029425"},"PeriodicalIF":3.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Esophageal cancer and precancerous lesions: focus on resident bacteria and fungi.","authors":"Liping Yuan, Yi Zhang, Chengli Wen, Sha Liu, Qin Zhang, Wen Yin, Qian Jia, Maolin Chen, Gang Luo, Mingming Deng, Muhan Lv, Wanmeng Xiao","doi":"10.1128/spectrum.03137-24","DOIUrl":"https://doi.org/10.1128/spectrum.03137-24","url":null,"abstract":"<p><p>Accumulating evidence highlights the pivotal role of microbiomes in cancer development. To elucidate the esophageal microbiome's characteristics during esophageal squamous cell carcinoma (ESCC) progression, normal tissues from 13 healthy controls (HC), paired esophageal squamous intraepithelial neoplasia (ESIN) lesional and adjacent (ESINA) tissues from 10 ESIN individuals, and ESCC lesional and adjacent (ESCCA) tissues from 12 ESCC individuals were collected. Following 16S rRNA and ITS sequencing, analyses encompassed α/β-diversity assessments, shared species identification, Type-I Taylor's Power Law Extensions (TPLE), linear discriminant analysis effect size (LEfSe), co-occurrence networks, receiver operating characteristic (ROC) curve analysis, and functional predictions. Distinct microbial signatures characterized HC, precancerous, and cancerous groups. The ESIN group exhibited unique microbial features, including diminished bacterial and fungal species sharing relative to the ESINA group and maximal <i>b</i> values in TPLE for both taxa. Despite the absence of significant bacterial composition differences between HC and ESIN in β-diversity analysis, notable alterations in the oral microbiome were observed. ESIN was marked by <i>Lactobacillus</i> and <i>Aspergillus</i> enrichment, while ESCC was predominantly associated with <i>Fusobacterium</i>, <i>Streptococcus</i>, and <i>Alternaria</i>. Disease progression led to shifts and reductions in species co-occurrence network interactions. <i>Aspergillus</i> demonstrated potential diagnostic value for ESIN, and its ratio to pathogenic functional clusters within network analysis significantly enhanced ESCC detection accuracy. Functional predictions revealed stage-specific pathway enrichments. These findings delineate microbiome alterations across ESCC stages, emphasizing ESIN-specific microbial shifts that may inform microbiome-based strategies for early detection and intervention.</p><p><strong>Importance: </strong>This study collected esophageal tissues through gastroscopic biopsy and conducted sequencing and analyses to explore the diversity, heterogeneity, key microbial composition, interaction networks, and functional predictions of resident bacteria and fungi in esophageal squamous cell carcinoma (ESCC) progression. The esophageal squamous intraepithelial neoplasia group showed the highest heterogeneity in oral microbiome and fungi, with certain species potentially contributing to ESCC progression. Targeting the oral microbiome in high-risk populations may thus provide a valuable approach for improving early diagnosis and potentially intervening in disease progression.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0313724"},"PeriodicalIF":3.7,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on <i>Lacticaseibacillus casei</i> TCS fermentation kinetic models and high-density culture strategy.","authors":"Chen Chen, Tianyu Guo, Di Wu, Jingyan Shu, Ningwei Huang, Huaixiang Tian, Haiyan Yu, Chang Ge","doi":"10.1128/spectrum.02590-24","DOIUrl":"https://doi.org/10.1128/spectrum.02590-24","url":null,"abstract":"<p><p>This study enhanced the production efficiency of Lacticaseibacillus casei TCS by optimizing medium composition and fermentation conditions for high-density culture. Initially, single-factor and orthogonal experimental designs and the response surface methodology were used to determine the optimal concentrations of medium. Subsequently, we applied the artificial neural network-genetic algorithm optimization method, which significantly increased the viable bacterial count. Fermentation kinetics were modeled using logistic growth and Luedeking-Piret models, which accurately predicted cell growth. Amberlite IRA 67, an anion exchange resin, effectively adsorbed lactic acid and maintained pH levels. Furthermore, the combined use of fed-batch fermentation and ion exchange alleviated the effects of acid inhibition, salt stress, and substrate limitation, resulting in a maximum cell density of 10.01 lg CFU/mL, a 9.3-fold increase over the basal medium. This study develops a robust and cost-effective strategy for the industrial production of <i>L. casei</i> TCS, significantly optimizing probiotic production processes. IMPORTANCE <i>Lacticaseibacillus casei</i> TCS possesses outstanding aromatic characteristics, making it suitable for producing fermented dairy products. The goal of cultivating <i>Lacticaseibacillus casei</i> TCS at high density is to increase production yields, overcome challenges related to acid inhibition, and optimize fermentation processes. This study employed an artificial neural network (ANN) and genetic algorithms (GA) to determine the ideal composition of the proliferation medium for <i>Lactobacillus casei</i> TCS. It constructed a dynamic model to track bacterial growth, product formation, and substrate consumption during fermentation, analyzing the process's dynamic patterns. Furthermore, by utilizing resin adsorption and fed-batch cultivation techniques, the production of lactic acid as a by-product was effectively minimized. This approach enabled <i>Lactobacillus casei</i> to multiply rapidly to high concentrations, laying a foundation for the industrial production of high-yield aroma starters. This advancement supports the bacterium's application in various sectors, including dairy processing and functional food production.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0259024"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A clinical and molecular analysis of <i>Candidozyma auris</i> strains from Romania, 2022-2023.","authors":"Marius Surleac, Adriana Mihaela Stanciu, Dragoș Florea, Simona Paraschiv, Daniela Tălăpan, Mirela Flonta, Carmen Cristina Vasile, Gabriel Adrian Popescu, Dan Oțelea","doi":"10.1128/spectrum.02809-24","DOIUrl":"https://doi.org/10.1128/spectrum.02809-24","url":null,"abstract":"<p><p><i>Candidozyma auris</i> (formerly <i>Candida auris</i>; <i>C. auris</i>) raises significant concerns for healthcare facilities due to its ability to cause severe systemic infections, increased resistance to antifungals, and high intra-hospital transmissibility. We conducted a retrospective study on 102 patients diagnosed in 2022 and 2023. Demographic, clinical, and epidemiologic data were collected from the hospital databases. <i>C. auris</i> was identified using MALDI-TOF systems, and antifungal susceptibility was determined with Micronaut. The isolates were sequenced using Illumina next-generation sequencing platforms. Molecular epidemiology analysis was performed with multiple bioinformatics approaches (phylogenetic tools, resistance genes-related predictions, and variant analyses). Most patients (80/102) were admitted to or had been recently transferred from intensive care units at the moment of <i>C. auris</i> detection. Most cases (57/102) were classified as infections; 29 of them were bloodstream infections. All patients had been treated with broad-spectrum antibiotics before <i>C. auris</i> isolation, and 75/102 had received antifungals. All 31 tested isolates showed resistance to fluconazole, 5 were resistant to amphotericin B, and they were all susceptible to echinocandins. Crude mortality for infected patients was 68.18%. The 31 analyzed sequences belonged to clade I and bore multiple resistance markers.IMPORTANCEHighly antifungal-resistant <i>Candidozyma auris</i> keeps spreading in regions previously free of this pathogen, stressing once again the need for active surveillance, flexible control measures, and antimicrobial stewardship. This study is seminal for our understanding of the <i>C. auris</i> outbreak in Romania, providing insights into the evolutionary dynamics and genomic diversity of the pathogen and highlighting clade-specific mutations possibly linked to antifungal resistance. By joining these molecular characteristics with clinical, epidemiological, and microbiology data, such as risk factors for acquiring <i>C. auris</i> and phenotypic antifungal susceptibility, the study can be instrumental for surveillance and infection control strategies that are essential due to the pathogen's high transmissibility and the global health threat that it poses.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0280924"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized <i>Legionella</i> expression strain for affinity purification of His-tagged membrane proteins eliminates major multimeric contaminant.","authors":"Sukhithasri Vijayrajratnam, Jonasz B Patkowski, Joshua Khorsandi, Wandy L Beatty, Shanmugapriya Kannaiah, Ahmet Hasanovic, Tamara J O'Connor, Tiago R D Costa, Joseph P Vogel","doi":"10.1128/spectrum.03222-24","DOIUrl":"https://doi.org/10.1128/spectrum.03222-24","url":null,"abstract":"<p><p>Polyhistidine tags are frequently used for isolating proteins through <u>ni</u>ckel-<u>n</u>itrilo<u>t</u>ri<u>a</u>cetic acid (Ni-NTA) affinity purification. However, proteins rich in histidine can also bind to the Ni-NTA resin, leading to contamination of the purification with undesired proteins. While attempting to purify the <i>Legionella pneumophila</i> Dot/Icm type IVB secretion system complex for single particle analysis, we encountered an unknown contaminant protein that bound to the Ni-NTA resin and formed uniform particles visible in negative stain electron microscopy (EM). Mass spectrometry identified this protein, which is encoded by the <i>Legionella</i> gene <i>lpg1596</i> as a homolog of enoyl-CoA hydratase. Modeling of Lpg1596 revealed surface-exposed histidine clusters, which likely explains its ability to bind to the Ni-NTA resin. Moreover, since enoyl-CoA hydratase homologs are known to multimerize, multimers of Lpg1596 would be large enough to be visible by negative stain EM. To address the problematic issue of Lpg1596 binding to the Ni-NTA resin, we constructed and analyzed a <i>L. pneumophila</i> ∆<i>lpg1596</i> mutant strain. Notably, Ni-NTA affinity purification of lysates from the ∆<i>lpg1596</i> strain did not contain the contaminant protein or generate observable particles. Since the ∆<i>lpg1596</i> mutant strain exhibited replication capabilities similar to the wild-type <i>L. pneumophila</i> in macrophages, its deletion will likely not affect pathogenesis studies. To facilitate the deletion of <i>lpg1596</i> in other <i>Legionella</i> strains, we developed a set of natural transformation vectors with various antibiotic resistance markers. In summary, we present a strategy for removing a common Ni-NTA resin binding protein contaminant in <i>L. pneumophila</i>, which improves single particle analysis outcomes.IMPORTANCENi-NTA purifications are a common method for isolating proteins with a His-tag, but they have a drawback: they often enrich unwanted proteins that are rich in histidines, which can contaminate the sample. We identified one such contaminant in <i>Legionella pneumophila</i>, a protein with homology to enoyl-CoA hydratases (Lpg1596). This protein binds to the Ni-NTA resin and forms particles that are observable in electron microscope (EM) images, interfering with the analysis. By removing the gene responsible for making this protein (<i>lpg1596</i>), the problem was solved, and no unwanted particles appeared in the EM images. The ∆<i>lpg1596</i> mutant strain is the first optimized strain for purifying His-tagged membrane proteins from <i>Legionella</i>, which can be used for further studies like single particle analysis.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0322224"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing <i>Candida auris</i> diagnosis: a comprehensive evaluation of VIASURE <i>Candida auris</i> real-time PCR detection kit for rapid diagnostic responses.","authors":"Blanca Dehesa-García, Henar Alonso, María Paz Peris, Blanca Fortuño, Pilar Abad, Antonio Rezusta, Ana Milagro","doi":"10.1128/spectrum.03111-24","DOIUrl":"https://doi.org/10.1128/spectrum.03111-24","url":null,"abstract":"<p><p><i>Candida auris</i>, a yeast that is highly resistant to antifungal treatments, represents a significant healthcare concern due to its rapid spread through surface contamination and patient colonization. A recent outbreak at the Miguel Servet University Hospital in Zaragoza, Spain, highlighted the urgent need for rapid diagnostic responses. The current 4-day duration for microbiological culture results hinders timely patient isolation and transmission prevention. This study aims to evaluate the VIASURE <i>Candida auris</i> Real-Time PCR Detection Kit (Certest Biotec) for diagnostic performance and analytical specificity compared to the standard methodology based on culture and MALDI-TOF MS characterization. From August 2023 to December 2023, the Microbiology Service of the Miguel Servet University Hospital processed 816 diagnostic samples. Accuracy testing resulted in adequate clinical validation values, as presented here: sensitivity, 0.98 (95% confidence interval [CI], 0.90 to 1); specificity, 1 (95% CI, 0.99 to 1); positive predictive value, 0.98 (95% CI, 0.90 to 1); and negative predictive value, 1 (95% CI, 0.99 to 1). The implementation of this molecular biology test in the laboratory promises to improve diagnostic efficiency by allowing rapid patient isolation, initiation of appropriate treatment, and effective isolation measures.</p><p><strong>Importance: </strong><i>Candida auris</i>, a resilient and antifungal-resistant yeast, poses a significant healthcare threat due to its rapid spread. A recent outbreak at a hospital in Zaragoza, Spain, emphasized the urgent need for faster diagnostics. The current four-day wait for culture results hampers timely patient isolation. This retrospective and comparative study demonstrates the favorable clinical parameters of a commercially available molecular diagnostic kit. The kit allows enhanced diagnostic efficiency, swifter patient isolation, and more effective control measures in the laboratory. In conclusion, the kit addresses the pressing challenges presented by <i>C. auris</i> in healthcare.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0311124"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly carbapenem-resistant <i>Achromobacter xylosoxidans</i> harboring <i>bla</i>_NDM-1 in Myanmar.","authors":"Maiko Kirikae, Satoshi Oshiro, Satomi Takei, Naeko Mizutani, Atsuo Itakura, Pan Ei Soe, Thi Thi Htoon, Swe Setk, Htay Htay Tin, Teruo Kirikae, Tatsuya Tada","doi":"10.1128/spectrum.00080-25","DOIUrl":"https://doi.org/10.1128/spectrum.00080-25","url":null,"abstract":"<p><p><i>Achromobacter xylosoxidans</i> is a multidrug-resistant, non-glucose-fermenting, gram-negative bacterium with intrinsic resistance to many antimicrobial agents. Between 2016 and 2017, five <i>A. xylosoxidans</i> isolates were obtained from five patients at three hospitals in Myanmar. Minimum inhibitory concentrations (MICs) against various antimicrobial agents were determined using the microdilution method. Whole genome sequencing was performed with the MiSeq and MinION platforms. Resistance genes and their surrounding structures were identified and compared. All five isolates were resistant to amikacin and aztreonam. Among them, one isolate, MyNCGM749, was resistant to imipenem and meropenem with MICs of 256 µg/mL and amikacin with MIC of >512 µg/mL but intermediate to ciprofloxacin with MIC of 2 µg/mL. The isolate carried <i>bla</i>_NDM-1 encoding metallo-β-lactamase, <i>bla</i>_PSE-1 encoding extended-spectrum-β-lactamase, and <i>bla</i>_OXA-114 (encoding intrinsic -β-lactamase present in <i>A. xylosoxidans</i>), along with five aminoglycoside modification encoding genes including <i>aac(6')-Ib</i>, <i>aph (6)-Id</i>, <i>aph(3'')-Ib</i>, <i>ant(4')-Iib</i>, and <i>aph(3')-VI</i> on its chromosome. The genetic structure surrounding <i>bla</i>_NDM-1 contained four IS<i>91</i> elements identical to those found in carbapenem-resistant <i>Pseudomonas asiatica</i> isolates in Myanmar. This is the first report of <i>A. xylosoxidans</i> in Myanmar. Although <i>A. xylosoxidans</i> harboring <i>bla</i>_NDM-1 has been reported in a single strain from India, its genomic details have not been previously described. This study indicates that the <i>bla</i>_NDM-1-containing structure flanked by IS<i>91</i> is spreading among gram-negative, non-glucose-fermenting bacteria in Myanmar and neighboring countries.IMPORTANCE<i>Achromobacter</i> species were originally environmental organisms that became opportunistic pathogens with multidrug resistance. <i>Achromobacter xylosoxidans</i> is associated with nosocomially acquired infections affecting multiple organ systems, including the respiratory and urinary tracts, and, less commonly, the cardiovascular and central nervous systems. To date, carbapenem-resistant <i>A. xylosoxidans</i> carrying carbapenemase-encoding genes has been reported in several countries, including Greece, India, Italy, Japan, Korea, Libya, and the Netherlands. In this molecular epidemiological study on <i>A. xylosoxidans</i> in Myanmar, we identified the genomic structure surrounding <i>bla</i>_NDM-1, flanked by IS<i>91</i>. This structure may facilitate the spread of non-glucose-fermenting gram-negative bacteria, such as <i>Achromobacter</i>, <i>Pseudomonas,</i> and <i>Stenotrophomonas</i> species, in Asian countries.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0008025"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One Health study of mobile colistin resistance (<i>mcr</i>) in <i>Salmonella enterica</i> in Canada, 2017-2022.","authors":"Ketna Mistry, David Thumbi, Xiao Rui Li, Audrey Charlebois, Brent P Avery, Anne E Deckert, Ashley C Cormier, Colleen Murphy, Ashley Kearney, Jennifer Campbell, Sara Christianson, David C Alexander, Sameh El Bailey, Sadjia Bekal, Linda Chui, Xiaofeng Ding, Tanis Dingle, David Haldane, Linda Hoang, Jessica Minion, Samir Patel, George Zahariadis, Celine Nadon, Michael R Mulvey, Carolee A Carson, Richard J Reid-Smith, Amrita Bharat","doi":"10.1128/spectrum.02156-24","DOIUrl":"https://doi.org/10.1128/spectrum.02156-24","url":null,"abstract":"<p><p>Colistin is a last-resort treatment for highly drug-resistant bacterial infections. Of 47,184 <i>Salmonella</i> isolates collected from 2017 to 2022 in Canada from human and animal/food sources, mobile colistin resistance (<i>mcr</i>) variants conferring colistin resistance were detected exclusively in humans (<i>n</i> = 15). These variants were <i>mcr</i>-1.1 (<i>n</i> = 7), <i>mcr</i>-3.1 (<i>n</i> = 5), <i>mcr</i>-3.2 (<i>n</i> = 2), and <i>mcr</i>-1.2 (<i>n</i> = 1). The most common <i>mcr</i>-containing serotypes were I 4,[5],12:i:- (<i>n</i> = 8) and Typhimurium (<i>n</i> = 3). The proportion of <i>Salmonella</i> carrying <i>mcr</i> genes remains low in Canada (0.03%).</p><p><strong>Importance: </strong>Colistin can be used in combination with other drugs as salvage therapy for extensively drug-resistant infections. If mobile colistin resistance (<i>mcr</i>) becomes widely disseminated in <i>Enterobacterales</i>, colistin will no longer be an option for salvage therapy in otherwise untreatable infections. While colistin is not commonly used to treat human <i>Salmonella</i> infections, <i>Salmonella</i> represents an important reservoir of <i>mcr</i> genes that may be transmitted to other gram-negative bacteria. Our aim was to determine the occurrence of <i>mcr</i> genes in <i>Salmonella</i> isolates collected from humans, food animals, and retail meats in Canada.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0215624"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}